Acoustic assembly for the hard of hearing



Nov. 21, 1939. c. A. VOLF ACOUSTIC ASSEMBLY FOHR- THE HARD OF HEARING.

Filed July 1, 19:56 5 Sheets-Sheet 1 -&ne or can ak/dion ww ae Iii Emmi

iii;

5M ZQ Combined Nov. 21, 1939. Q A VO| F 2,180,889

ACOUSTI C ASSEMBLY FOR THE HARD OF HAEARING Nov. 21, 1939. C. A. VOLF ACOUSTIC ASSEMBLY FOR THE HARD 0F HEARiNG 3 Sheet s Sheet 3 Filed July 1, 1936 Patented Nov. 21, 1939 umrso STATES,

,lATE-N T OFFICE AcoUs'rIc ASSEMBLY FOR THE mum of.

' panama Christian Volt, New York N. Y., assignor to" Clarence W. Sinn, New York; N. Y.

Application July 1, 1936, SerialNo. 88,43 4

2 Claims.

' This invention is an acoustic assembly, primarily for use by the hard of hearing.

One of the important objects of the invention is to provide an assembly which carries its 'own electrical supply, so that it does not need to be plugged into any commercial circuit. The independence of this inventionof any commercial circuit makes it useable at any point, regardless self-contained, with its own electrical supply, the invention, is very readily portable, and can be:

placed in any desired position on a desk, table, conference table, dining table, bedroom, and may beused in an automobile, in the woods, at the halls, etc. 1

Another important advantage ofthe invention is that it is highly sensitive so that it will pick up relatively weak or faint sounds. But it'is sensitive only in a definite or fixed direction, so that it can be placed to'pick up the desired sounds, such as the 'conversation of an individual, or the words of a minister or lecturer, but at the same time it will exclude other extraneous and undesirable sounds coming from other directions.

The transmitter assembly of this invention is conveniently placed in a' suitable carrying case and put into use simply by opening a portion or front slide. for example, of the case, without the necessity of removing the entire instrument.

The main advantages of the invention having thus been outlined, the present preferred structural embodiments of the invention will now be l briefly described.

The invention comprises a concave sound concentrator, mounted in a suitable housing, and in front of this sound concentrator and spaced from it, there is mounted a transmitter of more or less standard design, in such a position that sound waves picked. up by the concentrator will be directed onto the receiving face of the transmitter; Mounted on the outer face of the transmitter i' tures, opening into this resonant chamber, thus beaches, and in theaters, churches and lecture putting this resonant chamber in communication with the resonant chamber in the transmitter.

The transmitter assembly also carries its own battery, which may be a dry cell or cells of known design, which is also mounted in its own housing.

A magnetic amplifier is mounted for electrical connection both with the battery and the transmitter, and is preferably arranged to plug directly into the battery or dry cell.

There is also preferably provided, in the assembly, a voltmeter, which may be connected by a push button switch to the battery as desired;

for reading the condition ofthe battery at any time. A suitable housing is also provided for the voltmeter.

However, in place of the voltmeter, there could be mounted aclock, a barometer, a thermometer, a crystal radio set, or other desired type of apparatus. The use of such other instruments such as barometers, clocks, etc., would tend to camouflage the-,instrument as an instrument for use by the hard of hearing.

be made in several ways, such' for example, as a single casting having three compartments. The

The desired housings for the sound concenf trator, for the battery, and for the instrument,

housing may be made of metal, aluminum, Bekelite orother synthetic resin, etc. This casting might. be integral with a base or detachably secured to a base, the wires being concealed in the base.

- The several housings are preferably separated by partition walls and where such partitionwalls are metallic, they would serve to prevent inductive effect from one instrument to the other;

Where the several housings are made of wood, they could be'cut from a single block of wood, or could be made in three separate units, which could be glued, dove-tailed, or otherwise fastened together. I p

g The several component parts of the invention, as will appear from the drawings, are assembled into an attractive and well proportioned instru- -,ment which would .ordinarily not be recognizedas an aid for the hard of hearing, and at the same time is distinctly ornamental, attractive, and

modernist'ieinappearance all of which features are important in an article of this sort,

Reference will 'now be made to the accompanying drawings, illustrating in more detail the preferred embodiments of the invention.

In these drawings:

Fig. 1 is'a perspective view of the acoustic as-' sembly; 1 x

Fig. 2 is a plan view; Fig. 3 is a side elevation of the control side; Fig. 4 is a wiring diagram; I Fig. 5 is a side view of a modification; and 5 Fig. 6 is a side elevation of the receiving side of Fig. 5. A

' Referring now to these drawings, in which similar reference characters indicate similar parts, the assembly comprises a suitably re- 10 cessed base 2, on which is mounted a housing 4, for a concave sound concentrator 6, the sound concentrator being conveniently in the shape of a segment of a sphere, although it could have other curvatures, parabolic, for example, if de- 15 sired. The concentrator is preferably made of spun pewter, which has been found particularly efllcient for this purpose. The housing 4 is preferably of the simple rectangular form shown. Mounted directly in front of the sound conceng trator 8 and spaced therefrom is a transmitter 8, which may be of usual design, but is preferably of the type shown in my Patent No. 2,118, 993, dated May 31, 1938, having a concave receiving face I0, facing toward the concavesur- 25 face of the concentrator 6. The transmitter 8 is mounted in place by means of a small tube or pipe 12 secured by means of a bushing I4 to the concave face III of the transmitter, this pipe l2 passing through the housing 4 and being rigidly '30 held in place by means of a lock nut i6 and washer II, the latter being secured to pipe I2 and'to concentrator 8. .The usual. wires 4|,'42 from the transmitter 8 pass into the tube 12 through a suitable slot, thence through the tube H, for connection to a' rheostat and amplifier, as will be described.

The tubular supporting member l2 engages with the transmitter i8 and with the sound concentrator 8 substantially at their centers, leaving the peripheral portions ofthe transmitterand sound concentrator unobstructed for picking up sound .waves. The .tube' i2 is quite small and forv this reason also presents a minimum of interference. Furthermore; this tube l2 seems "to act as a resonance member in transmitting sound vibrations from the sound concentrator 8v to thetransmitter I8.\ As is evident from Fig. 2 the tubular support I2 is substantially coincident with the central transverse axis I! of the' concentrator 8 and the transmitter l0. f Mounted on the back of the transmitter 8 is r a ,substantially hemispherical cup or cap 22. I Sound waves coming toward the device flow around the cup and thence onto the concentrator 55 6. The interior of the cup also provides a resonance chamber or air cushion which is in communication by. means .of apertures 24 with the resonance chamber provided by the inside of the transmitter, back of the diaphragm. The interaction of those two resonance chambers lowers the pitch and improves the tone quality of the instrument- I The electrical supply for the apparatus is a dry cell or cells 26 mounted in a housing 28, also rectangular like the housing but somewhat narrower and lower than the housing 4.

Mounted on top of the housing 28, in a suitable recess, is a magnetic amplifier, 38, of a standard or usual design, which is adapted to plug directly into the battery 28 bymeans of plugs 32, the battery 28 being provided with suitable terminal-forming apertures for receiving these plugs.

A third housing member 34 is provided, preferably of rectangular shape, but smaller and narbolts or screws 58 to the housing 52.

rower than the housing 28, this housing being for a voltmeter 86 or for a clock, thermometer, barometer, or any other suitable apparatus, which instrument would tend to camouflage the appa: ratus as a hearing aid.

The three housing members 4, 28 and 34 form .a graceful, well-proportioned assembly of sim-' at the bottom. Where the housings are of metal,-

the partitions serve to prevent local inductive effects from one compartment to the other.

The several housings 4, 28 and 34 could also be made of wood, either by cutting them out from a single block of wood or by making them separately from smaller blocks of wood and gluing or otherwise securing them together so as to form substantially one unit, having compartments opening downwardly.

The several housings are mounted in the re cessed base 2, the housings being positioned in the recess so that most of the wiring will be in the recess directly below the several housing elements.

Referring to the wiring diagram of Fig. 4, the transmitter. 8 is connected by wires 4|, 42 to the wires 44 are plugged into the other end of the amplifier with a two-way plug.

The voltmeter 86 is connected to the battery 28 by means of wires 46 leading through a push button switch 41 mounted in the base 2.

The several wires, for convenience of inspection and'repair, may be connected to terminal elements 48 in the terminal 'block 50, which is mounted in a concealed position in the recess of the base member 2, underneath the several housings.

Referring now to the modifications shown in' Figs. and 6, the concave sound concentrator 6, made of pewter, is mounted in a housing52 having an ornamental'top 54.

Mounted in front of the concentrator 6 is a substantially hemispherical cup 22", secured in position by a plurality of arms 56, secured by The arms 58 are substantially U-shaped in cross section, to

provide a channel 60 therein facing toward th concentrator 8.

Mounted in the open end of the hemispherical so that the resonance chamber inside the transmitter is in communication with the resonance,

chamber or air cushion inside the hemispherical cup, an arrangement which improves the reception and clarity of the instrument, and lowers E118 pitch.

The wires 28 from the transmitter areconcealed'in the recess 58 in one of the arms 58 and thence lead into the magnetic amplifier 30', similar in all respects to the amplifier 30 of Fig. 3.

The battery 26in Fig. is mounted in a housing 62, similar in shape to housing 52, but narrower and shorter than housing 52 and provided with an ornamental top 62 like top of housing 52. On the inside of the ornamental top 62' is mounted the amplifier 30' in a concealed position. The amplifier 30' plugs into the battery 26 as before. v A third housing 64 is provided, which has an ornamental top like 54 in Fig. 6, this housing, however, being narrower and lower than'the housing 62. In this housing is mounteda voltmeter 36 or other device such as a clock, thermometer, barometer, etc.

The several housings 52, 62 and 64 may be made in a one-piece casting of metal or synthetic resin, or may be made of wood, as has been described, the compartments of the several housihgs opening downwardly and in communication with a relatively large recess 66 in the base 68. Inside the base 68 is mounted a plate for supporting-the wiring, the wiring block 50,

etc.

' The several parts in Figs. 5 and 6 are wired as shown in Fig. 4, the base member 68 being provided at any suitable point with a switch 41 for the voltmeter and with a combined rheostat and switch I for the transmitter.

While the preferred embodiments of the invention have been illustrated in some detail, it should be understood that the invention is not limitedto such details, but may be carried out in other ways.

I claim as my invention:

1. A sound-pick-up device for use on a table or desk, comprising in combination, a concave sound concentrator, a housing therefor, a transmitter positioned in front of and spaced from the concentrator and facing it, and having a resonance chamber therein, and a substantially hemispherical cup mounted on the back of the transmitter, for directing sound waves into the 

